From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755094AbaD1BcQ (ORCPT ); Sun, 27 Apr 2014 21:32:16 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:42865 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752486AbaD1B3U (ORCPT ); Sun, 27 Apr 2014 21:29:20 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Larry Finger" , "=?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?=" , "John W. Linville" Date: Mon, 28 Apr 2014 02:11:22 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 85/94] b43: Fix machine check error due to improper access of B43_MMIO_PSM_PHY_HDR In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.58-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Rafał Miłecki commit 12cd43c6ed6da7bf7c5afbd74da6959cda6d056b upstream. Register B43_MMIO_PSM_PHY_HDR is 16 bit one, so accessing it with 32b functions isn't safe. On my machine it causes delayed (!) CPU exception: Disabling lock debugging due to kernel taint mce: [Hardware Error]: CPU 0: Machine Check Exception: 4 Bank 4: b200000000070f0f mce: [Hardware Error]: TSC 164083803dc mce: [Hardware Error]: PROCESSOR 2:20fc2 TIME 1396650505 SOCKET 0 APIC 0 microcode 0 mce: [Hardware Error]: Run the above through 'mcelog --ascii' mce: [Hardware Error]: Machine check: Processor context corrupt Kernel panic - not syncing: Fatal machine check on current CPU Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffff9fffffff) Signed-off-by: Rafał Miłecki Acked-by: Larry Finger Signed-off-by: John W. Linville Signed-off-by: Ben Hutchings --- drivers/net/wireless/b43/phy_n.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) --- a/drivers/net/wireless/b43/phy_n.c +++ b/drivers/net/wireless/b43/phy_n.c @@ -3937,22 +3937,22 @@ static void b43_nphy_channel_setup(struc struct b43_phy_n *nphy = dev->phy.n; u16 old_band_5ghz; - u32 tmp32; + u16 tmp16; old_band_5ghz = b43_phy_read(dev, B43_NPHY_BANDCTL) & B43_NPHY_BANDCTL_5GHZ; if (new_channel->band == IEEE80211_BAND_5GHZ && !old_band_5ghz) { - tmp32 = b43_read32(dev, B43_MMIO_PSM_PHY_HDR); - b43_write32(dev, B43_MMIO_PSM_PHY_HDR, tmp32 | 4); + tmp16 = b43_read16(dev, B43_MMIO_PSM_PHY_HDR); + b43_write16(dev, B43_MMIO_PSM_PHY_HDR, tmp16 | 4); b43_phy_set(dev, B43_PHY_B_BBCFG, 0xC000); - b43_write32(dev, B43_MMIO_PSM_PHY_HDR, tmp32); + b43_write16(dev, B43_MMIO_PSM_PHY_HDR, tmp16); b43_phy_set(dev, B43_NPHY_BANDCTL, B43_NPHY_BANDCTL_5GHZ); } else if (new_channel->band == IEEE80211_BAND_2GHZ && old_band_5ghz) { b43_phy_mask(dev, B43_NPHY_BANDCTL, ~B43_NPHY_BANDCTL_5GHZ); - tmp32 = b43_read32(dev, B43_MMIO_PSM_PHY_HDR); - b43_write32(dev, B43_MMIO_PSM_PHY_HDR, tmp32 | 4); + tmp16 = b43_read16(dev, B43_MMIO_PSM_PHY_HDR); + b43_write16(dev, B43_MMIO_PSM_PHY_HDR, tmp16 | 4); b43_phy_mask(dev, B43_PHY_B_BBCFG, 0x3FFF); - b43_write32(dev, B43_MMIO_PSM_PHY_HDR, tmp32); + b43_write16(dev, B43_MMIO_PSM_PHY_HDR, tmp16); } b43_chantab_phy_upload(dev, e);